My Gen 2 had the same issue, as well as the hand guard being slightly off-center, and the muzzle brake being canted. I guessed mine was assembled on a Friday afternoon. Call me anal, obsessive, whatever, but I like my machines to be perfect. I don't expect anything to come from a manufacturer, at any price, to meet my standards. That is why my cars, motorcycles, guns, and other things that matter get thoroughly inspected and corrected as soon as I get them home. You'd be surprised at the flaws I have found. So I tore down the rifle and put it back together with everything properly torqued and aligned. I oiled the hand guard and of course, the coating on it soaked up the initial coat. But after a few trips to the range, subsequent cleanings and oiling, it has the same appearance of the rest of the rifle.
In the end, it may not matter how it looks, only how it performs. But I have found that how it (anything) performs is a reflection of the level of care it receives, which is often evident by how it looks. This is why Marines are obsessive about the maintenance of equipment, the proper wearing of the uniform and the fitness and training of the mind and body.